scholarly journals Voxelisation Algorithms and Data Structures: A Review

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8241
Author(s):  
Mitko Aleksandrov ◽  
Sisi Zlatanova ◽  
David J. Heslop
Keyword(s):  
Data Structure ◽  
Data Structures ◽  
State Of The Art ◽  
Algorithms And Data Structures ◽  
3D Objects ◽  
Digital Representations ◽  
Memory Footprint ◽  
Voxel Data ◽  
2D And 3D ◽  
Geometric Primitives

Voxel-based data structures, algorithms, frameworks, and interfaces have been used in computer graphics and many other applications for decades. There is a general necessity to seek adequate digital representations, such as voxels, that would secure unified data structures, multi-resolution options, robust validation procedures and flexible algorithms for different 3D tasks. In this review, we evaluate the most common properties and algorithms for voxelisation of 2D and 3D objects. Thus, many voxelisation algorithms and their characteristics are presented targeting points, lines, triangles, surfaces and solids as geometric primitives. For lines, we identify three groups of algorithms, where the first two achieve different voxelisation connectivity, while the third one presents voxelisation of curves. We can say that surface voxelisation is a more desired voxelisation type compared to solid voxelisation, as it can be achieved faster and requires less memory if voxels are stored in a sparse way. At the same time, we evaluate in the paper the available voxel data structures. We split all data structures into static and dynamic grids considering the frequency to update a data structure. Static grids are dominated by SVO-based data structures focusing on memory footprint reduction and attributes preservation, where SVDAG and SSVDAG are the most advanced methods. The state-of-the-art dynamic voxel data structure is NanoVDB which is superior to the rest in terms of speed as well as support for out-of-core processing and data management, which is the key to handling large dynamically changing scenes. Overall, we can say that this is the first review evaluating the available voxelisation algorithms for different geometric primitives as well as voxel data structures.

scholarly journals A research model in didactics of programming

2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Sylvia Rita Da Rosa ◽  
Federico Gabriel Gómez
Keyword(s):  
Data Structure ◽  
Computer Science ◽  
Data Structures ◽  
Search Algorithm ◽  
Empirical Studies ◽  
Specific Area ◽  
Research Model ◽  
Algorithms And Data Structures ◽  
Construction Of Knowledge ◽  
Knowledge Based

This paper presents a research model in didactics of programming elaborated within the theoretical framework of the epistemological theory of Jean Piaget. That theory explains the construction of scientific knowledge based on empirical studies made by Piaget over many years. The model arises from the analysis of the results of the application of principles of the theory, especially the triad of intra-inter-trans stages, to the empirical study of the construction of the concepts of algorithm, data structure and program. The elaboration of the model is a contribution to the development of the didactics of programming and, in general, of the didactics of computer science, since the model can be used in other computer science topics. Didactics is a specific area within computer science, with its own foundations and methods, which studies in depth topics related to education in the discipline. Two empirical studies about the construction of knowledge of algorithms and data structures, and of the corresponding programs as executable objects, are briefly described to illustrate the model.Both examples use a search algorithm (binary and linear) and the implementations are in the programming language C.

scholarly journals SetSketch

2021 ◽  
Vol 14 (11) ◽  
pp. 2244-2257
Author(s):  
Otmar Ertl
Keyword(s):  
Big Data ◽  
Data Structure ◽  
Data Structures ◽  
Similarity Search ◽  
State Of The Art ◽  
Use Cases ◽  
Distributed Environments ◽  
Jaccard Similarity ◽  
Big Data Applications ◽  
Better Than

MinHash and HyperLogLog are sketching algorithms that have become indispensable for set summaries in big data applications. While HyperLogLog allows counting different elements with very little space, MinHash is suitable for the fast comparison of sets as it allows estimating the Jaccard similarity and other joint quantities. This work presents a new data structure called SetSketch that is able to continuously fill the gap between both use cases. Its commutative and idempotent insert operation and its mergeable state make it suitable for distributed environments. Fast, robust, and easy-to-implement estimators for cardinality and joint quantities, as well as the ability to use SetSketch for similarity search, enable versatile applications. The presented joint estimator can also be applied to other data structures such as MinHash, HyperLogLog, or Hyper-MinHash, where it even performs better than the corresponding state-of-the-art estimators in many cases.

Explaining binomial heaps

1999 ◽  
Vol 9 (1) ◽  
pp. 93-104 ◽  
Author(s):  
RALF HINZE
Keyword(s):  
Data Structure ◽  
Programming Languages ◽  
Data Structures ◽  
Functional Programming ◽  
Priority Queue ◽  
Algorithms And Data Structures ◽  
Functional Programming Languages ◽  
Reading And Writing ◽  
Type Classes ◽  
Excellent Tool

Functional programming languages are an excellent tool for teaching algorithms and data structures. This paper explains binomial heaps, a beautiful data structure for priority queues, using the functional programming language Haskell (Peterson and Hammond, 1997). We largely follow a deductive approach: using the metaphor of a tennis tournament we show that binomial heaps arise naturally through a number of logical steps. Haskell supports the deductive style of presentation very well: new types are introduced at ease, algorithms can be expressed clearly and succinctly, and Haskell's type classes allow to capture common algorithmic patterns. The paper aims at the level of an undergraduate student who has experience in reading and writing Haskell programs, and who is familiar with the concept of a priority queue.

PROGRAMMING DATA STRUCTURE ALGORITHMS IN PYTHON

2021 ◽  
Vol 73 (1) ◽  
pp. 134-141
Author(s):  
A.R. Baidalina ◽  
◽  
S.A. Boranbayev ◽  
Keyword(s):  
Data Structure ◽  
Data Structures ◽  
Specific Problem ◽  
Binary Search ◽  
Complex Data ◽  
Algorithms And Data Structures ◽  
Search Trees ◽  
Python Language ◽  
The Subject ◽  
Programming Algorithms

The article discusses ways of programming algorithms for complex data structures in Python. Knowledge of these structures and the corresponding algorithms is necessary when choosing the best methods for developing various software. When studying the subject "Algorithms and Data Structures", it is important to understand the essence of data structures. This is due to the fact that manipulating a data structure to fit a specific problem requires an understanding of the essence and algorithms of this data structure. Examples of programming algorithms related to dynamic lists and binary search trees in the currently widely used Python language are given. The algorithms for traversing the graph in depth and breadth are optimally and clearly implemented using the Python dictionary.

Suffix array for multi-pattern matching with variable length wildcards

2021 ◽  
Vol 25 (2) ◽  
pp. 283-303
Author(s):  
Na Liu ◽  
Fei Xie ◽  
Xindong Wu
Keyword(s):  
Dynamic Programming ◽  
Data Structure ◽  
Pattern Matching ◽  
Edit Distance ◽  
State Of The Art ◽  
Suffix Array ◽  
Variable Length ◽  
Distance Method ◽  
Efficient Data ◽  
Comparison Algorithms

Approximate multi-pattern matching is an important issue that is widely and frequently utilized, when the pattern contains variable-length wildcards. In this paper, two suffix array-based algorithms have been proposed to solve this problem. Suffix array is an efficient data structure for exact string matching in existing studies, as well as for approximate pattern matching and multi-pattern matching. An algorithm called MMSA-S is for the short exact characters in a pattern by dynamic programming, while another algorithm called MMSA-L deals with the long exact characters by the edit distance method. Experimental results of Pizza & Chili corpus demonstrate that these two newly proposed algorithms, in most cases, are more time-efficient than the state-of-the-art comparison algorithms.

scholarly journals Cache-efficient sweeping-based interval joins for extended Allen relation predicates

2021 ◽  
Author(s):  
Danila Piatov ◽  
Sven Helmer ◽  
Anton Dignös ◽  
Fabio Persia
Keyword(s):  
Data Structure ◽  
Experimental Evaluation ◽  
State Of The Art ◽  
Temporal Databases ◽  
Access Method ◽  
Wide Range ◽  
Interval Relation ◽  
Cache Efficient ◽  
Join Algorithms ◽  
Better Than

AbstractWe develop a family of efficient plane-sweeping interval join algorithms for evaluating a wide range of interval predicates such as Allen’s relationships and parameterized relationships. Our technique is based on a framework, components of which can be flexibly combined in different manners to support the required interval relation. In temporal databases, our algorithms can exploit a well-known and flexible access method, the Timeline Index, thus expanding the set of operations it supports even further. Additionally, employing a compact data structure, the gapless hash map, we utilize the CPU cache efficiently. In an experimental evaluation, we show that our approach is several times faster and scales better than state-of-the-art techniques, while being much better suited for real-time event processing.

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